Ribbon mechanism for typewriters



Aug. 19. 1924.

. DE WITT C. HARRIS RIBBON MECHANISM FOR TYPEWRITERS Find nay' s, 192:.

3 Sheets-Sheet 2 Aug.' 179, 1924;- 1,505,6193

Y l I DE WITT C. HARRIS RIBBON Mvcmmrsm Fon TYPEwRITERs File nay :5,1922s sheets-sneer 3 fag, lr6

` dotted line 4 of Fig. l.

Patented Aug. 1 9, 1924,

DE WITT C. HARRIS, 0F PINELAND, FLORIDA.

RIBBON MEHANISM FR T'YIEEWRITERS.

Application filed May 3,

To all whom. 'it may concern Be it known that I, Dn `Wrr'r C. Ilanms, acitizenof the United States, residing at Pineland, in the county of Leeand @tate of Florica, have invented a certain new and useful RibbonMechanism for Typewriters, of which the following is a specification.

This invention relates particularly to improved means for vibrating theribbon, for shifting from one color or field to the other, and forsilencing the vibratorwhen it is desired to make imprints without usingthe ribbon, as when cutting stencils.

In the accompanying drawings, Figure l is a fragnrental longitudinalvertical central sectional view of one form of typewriter embodying thefeatures of my invention. Fig. 2 is adetail View of the type guide andthe ribbon guide. flfig. 3 is a horizontal sectional view showing aportion ofthe ribbon-vibrating mechanism, and vibrator-controllingmechanism in plan view. Fig. a is afragmental vi-ew of thevibrator-controlling mechanism, as viewed from the rear, that is to say,in the plane indicated by Fig. 5 is a Vview on an enlarged scale ofcertain of the parts shown in Fig. l. Fig. G is a view takenapproximately in the plane of dotted line 6 6 of Fig. 5.

lVhiie the present invention in its broader aspects is applicable totypewriters of various classes, it is herein shown as embodied in afront-strike typewriter of the construction fully disclosed in `mycopending appli- I cation Serial No. 541,930 tiled M'arclrS, 1922,

In this application I have described and claimed a complete typewriterwhich comprises a plurality of independent or selfcontained sections orunits so constructed and related that they may be separatelymanufactured and assembled as units and then may be quickly associatedtogether to form a complete machine, the said units being also readilydemountable lor separable from each other to facilitate cleaning,adjustment or repair and to permit of the replacement cf a vworn unit bya new unit when necessary.

For the sake of lucidity I will herein describe briefly the generalconstruction of this type of machine without, however, intending tolimit the invention to such type; Referring to Fig. ,1 of thedrawings,the machine comprises an external lsection composed of a framework Awhich carries ceri922. Serial No. 558,077.

- This will be herein referred to as the frame unit. The machine alsocomprises an internal section hereinafter termed the action unit, whichincludes a frame or support B and operating mechanism thereon, said unitas a who-le being insert'able into the frame unit through the lower endof the latter, the two units being provided with complementary lockingdevices (not herein shown) which are arranged to be instantly operableby the operator-s fingers to lock the two units together or unlock themto permit of their separation.

This action unit comprises in the present :instance a verticallyshiftable type bar segment C on which are pivoted the set of type bars,one being herein shown at D. E designates the type guidel which is fixedto and extends upwardly from the segment tl. @ne of the series of keylevers is shown at F, said lever being pivoted upon a rod or devices IIto the type bar. The action unit frame is provided with the usual feet Ito rest upon al desk or other suitable support, and the frame unit restsupon and is supported by the action unit frame. In separating the twounits the frame unit is lifted bodily in a vertical direction off theaction unit without disturbing the latter. The operating mechanism onthe respective units comprises parts which are arranged to assume anoperative relationship to each other automatically in the act ofassembling the two units. 4

In the machine disclosed in my said companion application there is athird demountable unit which Vcomprises the carriage. I have deemed `itunnecessary to show this unit in this application, the platen only beingdiagi'ammatically shown at K.

Referring now to thek ribbon mechanism which is the subject .matter ofthe present application, the ribbon itself is indicated by referencenume al l, one ofthe pair of spools on which it is wound beingdesignated 2. This spool is mounted upon the upper end of a verticalshaft 3 suitably supported in a bearing in the frame unit, said shaftand the spool thereon being driven by suitable means herein shown ascomprising a horizontally extending shaft 4; and a pair of intermeshingspiral gears 5 xed lon the shafts 3 and 4; respectively. That portion ofthe ribbon which is in proximity to shaft G andbeing connected bysuitable the platen is carried in two guides 7 arranged at oppositesides of the printing point, said guides being secured to a vibratorstein 8 which is mounted on the type guide E for vertical reciprocation.The lower end of the stem S is pivotally connected at 9 (Fig. 5) t0 theforward end of an arm 10 which is integral with or otherwise attached toa cam structure 11. The latter' is pivoted at 12 to a bracket 13 fixedto the frame' B of the action unit. The cam structure 11 contains twocam slots of different forms, one being adapted to provide sufficientmovement to aise the ribbon guides 7 from their normal position to aposition where the upper field of the ribbon may be struck by the type,and the other cam beingof such form as to provide sufficiently greatermovement to bring the lower field of the ribbon into printing position.In the present embodiment, the cam structure 11 consists of a piece ofsheet metal vfolded to form two spaced parallel sides and a rearconnecting web 14. In one side of the cam structure is formed a cam slot15, and in the other side there is a cam slot 1G.

Means in the nature of a pivoted arm is provided to engage the camstructure 11, said arm being laterally shiftable to engage either camslot or to lie in an ineffective position between the sides of the camstructure. IVhile power to swing the abovementioned arm may be obtainedfrom any suitable source, it is herein shown as actuated by meansincluding a universal bar 17 connected at its ends to arms 18 which arepivoted upon the pivot G for the key levers "F. The key levers F havedownwardly extending arms 19 with which the universal bar 17 normally isin contact. At the middle of the universal bar 17 is arearwardlyextending projection 20 arranged to engage aA` short arm orlug 21 attached to a rock shaft 22. The shaft- 22 extends transverselyof the machine from the right hand side thereof, t0 a point about midwayof the sides the machine. Fixed to the inner end of the shaft 22 is arearwardly-extending arm 23. On opposite sides of the free end of saidarm are rollers 24- adapted to lie in the cam slots 15 and 1G. Said camslots are of suoh form that when the ribbon -vibrator is'in its positionof rest, the lower said sides and out of engagement with both cam slots.A coiled contractile spring 25 connected at` one end to the pivot 12 andat its other end to a lug 26 rigid with the shaft 22, normally holds thearm 23 in its lower-most position.

The means for longitudinally shifting the shaft 22 to place the rollers24; in eugagemeut with the desired cani slot or in central neutralposition nray partake of various forms. That herein shown comprises alever 27 pivoted to the frame B of' the aetion unit to swing upon thevertical axis 2S (Figs. 1 and 3). The rearwardly extending arm of thelever 27 has a bent end which embraces the shaft 22 and lies betweenshoulders 29 (Fig. G) on said shaft. To the forwardly-extending arm ofthe lever 27 is pivoted a link 3() (Figs. 3 and 4) which extends to thelongitudinal median plane of the machine and is there pivoted at 31 tothe downwardly-extending arm of a three-arm levcr 32. Said three-armlever is mounted to swing upon a horizontal axis 33 and comprises twooppositely-extending arms Set which extend freely through openings inthe lower portions of two vertical parallel plungers 35. These plungersare guided in the frame B for vertical movement. In an overlying portionof the frame A are mounted two plungers 36 and 37 having at their lowerends heads 38 which engage the upper ends of the plungers 35. The upperends of the plungers 3G and 37 constitute linger keys adapted fordepression by the operator. It will be seen that when the plunger 3G isdepressed, the three-arm lever 32 will be swung in the direction to pushthe shaft 22 into position to place the arm 23 in engagement with thecam slot 15, this cam slot being of such form that the oscillation ofthe arm 23 will cause only suilicient movement of the ribbon guides 7 tolace the upper field (for example, the black eld) in printing position.When the plunger 37 is depressed, the shaft 22 will be slid 1n theopposite direction to place the arm 23 in engagement with the cam slot16, whereby swinging movement 0f the arm 23 will cause an increasedrange of movement of the ribbon guides 7, such movement being sullieientto place the lower or red field of the ribbon at the printing line.

If the operator depresscs the plungers 36 and 37 to an equal extent, thearm 23 will be caused to occupy a central position midway between theslotted sides of the cam structure 11, thus disconnecting the ealnstructure 11 from the arm 23 and permitting operation of the machinewith the ribbon at rest in its lower or ineffective position. This isthe condition desired when work such as stencil cutting is to be done.

Means is provided for yieldingly holding the shaft 22 in any one of itsthree positions of adjustment. While any suitable means may be employedfor this purpose, I have herein shown two locking balls 40 lying inopenings in the upper and lower sides of a stationary supportingstructure 41, these balls being adapted to engage in peripheral grooves42 formed in the shaft 22. Leafl springs 43 serve to press the balls 4()yieldingly against opposite sides of the shaft 22.

Referring again to the demountable type of machine in which theinvention is herein shown as embodied, it will be seen from Fig. l thatthe ribbon and its driving mechanism, that is, the mechanism forrotating the ribbon spools 2, are mounted upon the frame unit A and thatthe plungers 36 and 37 are also mounted upon this unit. Theribbonvibrating mechanism including' the means for shifting colors andfor silencing the ribbon guide is mounted on the action unit B. Then thetwo units are to be separated the ribbon l is withdrawn from the guides7 and the frame unit may then be lifted bodily off from the action unit,leaving the latter standing upon the desk or other support. Inreassembling the two units the plungers 36 and 37 automatically assumetheir operative relation to the plungers 35. The ribbon-drivingmechanism and the ribbon-vibrating and color-shift mechanism are somounted and located upon the respective units A and B that they do notinterfere with the separation and assembly of the two units.

I claim as my invention:

l. A typewriter having, in combination, ribbon-vibrating mechanismincluding a rock shaft extending transversely of the typewriter, a leverpivoted between its ends at one side of the typewriter, the rear arm ofsaid lever being connected to said shaft, an operating element locatedin the longitudinal median plane of the typewriter, a connection betweensaid element and the forward arm of said lever, and two finger keysarranged to move said element in opposite directions.

2. A typewriter having, in combination, a ribbon carrier, two camsrigidly secured together and connected to said carrier, a rock shaft, anarm on the shaft adapted to engage either of the cams or to lie in thespace between the cams, a `key-lever universal bar arranged to move theshaft around its axis, and key-operated means for longitudinally movingthe shaft.

3. A typewriter having, in combination, a frame unit and an action unitarranged to be readily separated and assembled, ribbondriving andsupporting mechanism mounted on the frame unit and ribbon-vibratingmechanism mounted on the action unit.

4. A typewriter having, in combination, a frame unit and an action unitarranged to be readily separated and assembled, ribbonsupporting anddriving means mounted on the frame unit, ribbon-vibrating and colorshiftmeans mounted on the action unit, and means mounted on the frame unitfor operating the ribbon color-shift means.

5. A typewriter having, in combination, a ribbon carrier, two spacedcams connected by an integral web, a rock shaft, an arm rigidly securedto said yrock shaft and adapted to engage either of said cams or to liein the space between them, means for rotating said shaft to actuate saidcams, and means for longitudinally moving said shaft to selectivelyposition said arm with relation to said cams.

In testimony whereof, I have hereunto affixed my signature.

DE WITT C. HARRIS.

